Heretofore, a substrate for DNA diagnosis has been used as one means of gene analysis, etc. A DNA-immobilization substrate accepts a large number of DNA fragments and oligonucleotides aligned on the surface of its solid phase, and it is widely noticed in the field of biochemical, molecular biological and gene engineering studies or medical examinations, as making it possible to treat a large number minor samples and to analyze the reaction data through spectroscopy in a rapid and simplified manner.
Though such DNA-immobilization substrates are extremely expensive, a method of reusing the used substrates for again immobilizing any other DNA thereon has not as yet been developed. Therefore, used substrates are generally disposed of, and even though they are reused, the DNA having been previously immobilized thereon may still remain on them and most used substrates are no longer practicable.
The present invention is to solve the above-mentioned problems and to provide a method of reusing once-used DNA-immobilization substrates for efficient utilization of expensive DNA-immobilization substrates, in which the reused DNA-immobilization substrates have the same performance as that of new substrates with no trouble in practical use, and the invention is to reduce the economical and technical load to DNA-immobilization substrate users.